<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-11-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0002080023</issuerCik>
        <issuerName>Viking Acquisition Corp I</issuerName>
        <issuerTradingSymbol>VACI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002094616</rptOwnerCik>
            <rptOwnerName>Wohlin Hakan</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VIKING ACQUISITION CORP I</rptOwnerStreet1>
            <rptOwnerStreet2>900 3RD AVE FL 10TH</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002079951</rptOwnerCik>
            <rptOwnerName>Viking Acquisition Sponsor I, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>900 THIRD AVENUE, 10TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A ordinary shares</value>
            </securityTitle>
            <transactionDate>
                <value>2025-11-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>350000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8016667</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Viking Acquisition Sponsor I, LLC</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>11.5</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-11-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>116666</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A ordinary shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>116666</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>116666</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Viking Acquisition Sponsor I, LLC</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 7,666,667 Class B ordinary shares previously reported by the reporting person (the &quot;Sponsor&quot;) in the Form 3 filed by the Reporting Persons on October 30, 2025. These Class B ordinary shares are convertible into Class A ordinary shares and will automatically convert upon the closing of the Issuer's initial business combination. The Class B ordinary shares held by the Sponsor are beneficially owned by (a) KingsRock Viking Acquisition, LLC, which is an affiliate of and managed by KingsRock Advisors, LLC, and which has an approximately 87% interest in the shares, and (b) KingsRock Advisors, LLC, which has an approximately 13% interest in the shares. Mr. Wohlin is the Chief Executive Officer of the Sponsor (as well as KingsRock Viking Acquisition, LLC and KingsRock Advisors, LLC), and has the voting and dispositive power over the shares held by the Sponsor.</footnote>
        <footnote id="F2">The Class A ordinary shares are held directly by the Sponsor.  The Class A shares held by the Sponsor are beneficially owned by KingsRock Viking Acquisition, LLC.</footnote>
        <footnote id="F3">The Private Warrants will become exercisable on the later of 30 days after the completion of the Issuer's initial business combination or 12 months from the completion of the Issuer's initial public offering.</footnote>
        <footnote id="F4">The Private Warrants will expire on the fifth anniversary of the Issuer's completion of its initial business combination.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Hakan Nils Wohlin</signatureName>
        <signatureDate>2025-11-04</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Hakan Nils Wohlin, as managing member  of Viking Acquisition Sponsor I, LLC</signatureName>
        <signatureDate>2025-11-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
